Abstract: The article discusses the results of a study of the features of the functional state of the cardiorespiratory system in children in the conditions of the Southern Aral Sea region. The study of the patency of various parts of the tracheobronchial tree showed that boys tend to increase bronchial patency with age. The increase in bronchial patency with the age of children with insignificant differences in the value of the vital capacity of the lungs can be attributed to the regional features of the external respiration system. It has been established that there is a relationship between physical development and functional characteristics of the circulatory system in children born and living in the South Aral Sea region. The data obtained suggest that the circulatory system in children is very sensitive to adverse environmental factors in the Southern Aral Sea region, thereby reducing their adaptive capacity and contributing to the formation of conditions for the development of diseases.